1 /* 2 * Copyright (C) 2009 by Matthias Ringwald 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 21 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 27 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 /* 33 * l2cap.c 34 * 35 * Logical Link Control and Adaption Protocl (L2CAP) 36 * 37 * Created by Matthias Ringwald on 5/16/09. 38 */ 39 40 #include "l2cap.h" 41 #include "hci.h" 42 #include "hci_dump.h" 43 #include "debug.h" 44 45 #include <stdarg.h> 46 #include <string.h> 47 48 #include <stdio.h> 49 50 // size of HCI ACL + L2CAP Header for regular data packets 51 #define COMPLETE_L2CAP_HEADER 8 52 53 // minimum signaling MTU 54 #define L2CAP_MINIMAL_MTU 48 55 #define L2CAP_DEFAULT_MTU 672 56 57 // nr of buffered acl packets in outgoing queue to get max performance 58 #define NR_BUFFERED_ACL_PACKETS 3 59 60 // offsets for L2CAP SIGNALING COMMANDS 61 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 62 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 63 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 64 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 65 66 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 67 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 68 69 static uint8_t * sig_buffer = NULL; 70 static linked_list_t l2cap_channels = NULL; 71 static linked_list_t l2cap_services = NULL; 72 static uint8_t * acl_buffer = NULL; 73 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 74 75 void l2cap_init(){ 76 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 77 acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 78 79 // 80 // register callback with HCI 81 // 82 hci_register_packet_handler(&l2cap_packet_handler); 83 } 84 85 86 /** Register L2CAP packet handlers */ 87 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 88 } 89 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 90 packet_handler = handler; 91 } 92 93 // notify client/protocol handler 94 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 95 if (channel->packet_handler) { 96 (* (channel->packet_handler))(type, channel->local_cid, data, size); 97 } else { 98 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 99 } 100 } 101 102 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 103 uint8_t event[17]; 104 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 105 event[1] = sizeof(event) - 2; 106 event[2] = status; 107 bt_flip_addr(&event[3], channel->address); 108 bt_store_16(event, 9, channel->handle); 109 bt_store_16(event, 11, channel->psm); 110 bt_store_16(event, 13, channel->local_cid); 111 bt_store_16(event, 15, channel->remote_cid); 112 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 113 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 114 } 115 116 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 117 uint8_t event[4]; 118 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 119 event[1] = sizeof(event) - 2; 120 bt_store_16(event, 2, channel->local_cid); 121 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 122 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 123 } 124 125 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 126 uint8_t event[16]; 127 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 128 event[1] = sizeof(event) - 2; 129 bt_flip_addr(&event[2], channel->address); 130 bt_store_16(event, 8, channel->handle); 131 bt_store_16(event, 10, channel->psm); 132 bt_store_16(event, 12, channel->local_cid); 133 bt_store_16(event, 14, channel->remote_cid); 134 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 135 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 136 } 137 138 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 139 // track credits 140 channel->packets_granted += credits; 141 // log_dbg("l2cap_emit_credits for cid %u, credits now: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 142 143 uint8_t event[5]; 144 event[0] = L2CAP_EVENT_CREDITS; 145 event[1] = sizeof(event) - 2; 146 bt_store_16(event, 2, channel->local_cid); 147 event[4] = credits; 148 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 149 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 150 } 151 152 void l2cap_hand_out_credits(){ 153 linked_item_t *it; 154 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 155 if (!hci_number_free_acl_slots()) return; 156 l2cap_channel_t * channel = (l2cap_channel_t *) it; 157 if (channel->state != L2CAP_STATE_OPEN) continue; 158 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 159 l2cap_emit_credits(channel, 1); 160 } 161 } 162 } 163 164 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 165 linked_item_t *it; 166 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 167 l2cap_channel_t * channel = (l2cap_channel_t *) it; 168 if ( channel->local_cid == local_cid) { 169 return channel; 170 } 171 } 172 return NULL; 173 } 174 175 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 176 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 177 if (channel) { 178 return channel->remote_mtu; 179 } 180 return 0; 181 } 182 183 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 184 // log_dbg("l2cap_send_signaling_packet type %u\n", cmd); 185 va_list argptr; 186 va_start(argptr, identifier); 187 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 188 va_end(argptr); 189 return hci_send_acl_packet(sig_buffer, len); 190 } 191 192 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 193 194 // check for free places on BT module 195 if (!hci_number_free_acl_slots()) { 196 log_dbg("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 197 return -1; 198 } 199 int err = 0; 200 201 // find channel for local_cid, construct l2cap packet and send 202 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 203 if (channel) { 204 // track sending 205 ++channel->packets_outgoing; 206 if (channel->packets_granted > 0){ 207 --channel->packets_granted; 208 // log_dbg("l2cap_send_internal cid %u, 1 credit used, credits left %u; outgoing count %u\n", 209 // local_cid, channel->packets_granted, channel->packets_outgoing); 210 } else { 211 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 212 } 213 214 // 0 - Connection handle : PB=10 : BC=00 215 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 216 // 2 - ACL length 217 bt_store_16(acl_buffer, 2, len + 4); 218 // 4 - L2CAP packet length 219 bt_store_16(acl_buffer, 4, len + 0); 220 // 6 - L2CAP channel DEST 221 bt_store_16(acl_buffer, 6, channel->remote_cid); 222 // 8 - data 223 memcpy(&acl_buffer[8], data, len); 224 225 // send 226 err = hci_send_acl_packet(acl_buffer, len+8); 227 } 228 229 l2cap_hand_out_credits(); 230 231 return err; 232 } 233 234 // open outgoing L2CAP channel 235 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 236 bd_addr_t address, uint16_t psm, uint16_t mtu){ 237 238 // alloc structure 239 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 240 // TODO: emit error event 241 if (!chan) return; 242 243 // fill in 244 BD_ADDR_COPY(chan->address, address); 245 chan->psm = psm; 246 chan->handle = 0; 247 chan->connection = connection; 248 chan->packet_handler = packet_handler; 249 chan->remote_mtu = L2CAP_MINIMAL_MTU; 250 chan->local_mtu = mtu; 251 252 // flow control 253 chan->packets_granted = 0; 254 chan->packets_outgoing = 0; 255 256 // set initial state 257 chan->state = L2CAP_STATE_CLOSED; 258 chan->sig_id = L2CAP_SIG_ID_INVALID; 259 260 // add to connections list 261 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 262 263 // send connection request 264 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 265 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 0); 266 } 267 268 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 269 // find channel for local_cid 270 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 271 if (channel) { 272 channel->sig_id = l2cap_next_sig_id(); 273 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 274 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 275 } 276 } 277 278 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 279 linked_item_t *it; 280 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 281 l2cap_channel_t * channel = (l2cap_channel_t *) it; 282 if ( ! BD_ADDR_CMP( channel->address, address) ){ 283 if (channel->state == L2CAP_STATE_CLOSED) { 284 // failure, forward error code 285 l2cap_emit_channel_opened(channel, status); 286 // discard channel 287 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 288 free (channel); 289 } 290 } 291 } 292 } 293 294 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 295 linked_item_t *it; 296 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 297 l2cap_channel_t * channel = (l2cap_channel_t *) it; 298 if ( ! BD_ADDR_CMP( channel->address, address) ){ 299 if (channel->state == L2CAP_STATE_CLOSED) { 300 // success, start l2cap handshake 301 channel->handle = handle; 302 channel->sig_id = l2cap_next_sig_id(); 303 channel->local_cid = l2cap_next_local_cid(); 304 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 305 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 306 } 307 } 308 } 309 } 310 311 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 312 313 bd_addr_t address; 314 hci_con_handle_t handle; 315 linked_item_t *it; 316 int i; 317 318 switch(packet[0]){ 319 320 // handle connection complete events 321 case HCI_EVENT_CONNECTION_COMPLETE: 322 bt_flip_addr(address, &packet[5]); 323 if (packet[2] == 0){ 324 handle = READ_BT_16(packet, 3); 325 l2cap_handle_connection_success_for_addr(address, handle); 326 } else { 327 l2cap_handle_connection_failed_for_addr(address, packet[2]); 328 } 329 break; 330 331 // handle successful create connection cancel command 332 case HCI_EVENT_COMMAND_COMPLETE: 333 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 334 if (packet[5] == 0){ 335 bt_flip_addr(address, &packet[6]); 336 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 337 l2cap_handle_connection_failed_for_addr(address, 0x16); 338 } 339 } 340 break; 341 342 // handle disconnection complete events 343 case HCI_EVENT_DISCONNECTION_COMPLETE: 344 // send l2cap disconnect events for all channels on this handle 345 handle = READ_BT_16(packet, 3); 346 // only access next element to allows for removal 347 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 348 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 349 if ( channel->handle == handle ){ 350 // update prev item before free'ing next element 351 it->next = it->next->next; 352 l2cap_finialize_channel_close(channel); 353 } 354 } 355 break; 356 357 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 358 for (i=0; i<packet[2];i++){ 359 handle = READ_BT_16(packet, 3 + 2*i); 360 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i); 361 while (num_packets) { 362 363 // find channels with max nr of pending outgoing packets 364 l2cap_channel_t * fullest_channel = NULL; 365 int max_nr_pending = 0; 366 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 367 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 368 if (channel->packets_outgoing > max_nr_pending){ 369 fullest_channel = channel; 370 max_nr_pending = channel->packets_outgoing; 371 } 372 } 373 374 // decrease packets 375 if (fullest_channel) { 376 fullest_channel->packets_outgoing--; 377 // log_dbg("hci_number_completed_packet (l2cap) for cid %u, outgoing count %u\n", 378 // fullest_channel->local_cid, fullest_channel->packets_outgoing); 379 } else { 380 log_err("hci_number_completed_packet but no outgoing packet in records\n"); 381 } 382 383 // handled! 384 num_packets--; 385 } 386 } 387 l2cap_hand_out_credits(); 388 break; 389 390 // HCI Connection Timeouts 391 case L2CAP_EVENT_TIMEOUT_CHECK: 392 handle = READ_BT_16(packet, 2); 393 l2cap_channel_t * channel; 394 int used = 0; 395 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 396 channel = (l2cap_channel_t *) it; 397 if (channel->handle == handle) { 398 used = 1; 399 } 400 } 401 if (!used) { 402 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 403 } 404 break; 405 406 default: 407 break; 408 } 409 410 // pass on 411 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 412 } 413 414 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 415 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 416 l2cap_finialize_channel_close(channel); 417 } 418 419 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 420 421 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 422 l2cap_service_t *service = l2cap_get_service(psm); 423 if (!service) { 424 // 0x0002 PSM not supported 425 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 426 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 427 return; 428 } 429 430 hci_connection_t * hci_connection = connection_for_handle( handle ); 431 if (!hci_connection) { 432 log_err("no hci_connection for handle %u\n", handle); 433 // TODO: emit error 434 return; 435 } 436 // alloc structure 437 // log_dbg("l2cap_handle_connection_request register channel\n"); 438 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 439 // TODO: emit error event 440 if (!channel) return; 441 442 // fill in 443 BD_ADDR_COPY(channel->address, hci_connection->address); 444 channel->psm = psm; 445 channel->handle = handle; 446 channel->connection = service->connection; 447 channel->packet_handler = service->packet_handler; 448 channel->local_cid = l2cap_next_local_cid(); 449 channel->remote_cid = source_cid; 450 channel->local_mtu = service->mtu; 451 channel->remote_mtu = L2CAP_MINIMAL_MTU; 452 453 // set initial state 454 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 455 456 // temp. store req sig id 457 channel->sig_id = sig_id; 458 459 // add to connections list 460 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 461 462 // emit incoming connection request 463 l2cap_emit_connection_request(channel); 464 } 465 466 void l2cap_accept_connection_internal(uint16_t local_cid){ 467 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 468 if (!channel) { 469 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 470 return; 471 } 472 473 // accept connection 474 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 475 476 // set real sig and state and start config 477 channel->sig_id = l2cap_next_sig_id(); 478 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 479 uint8_t config_options[4]; 480 config_options[0] = 1; // MTU 481 config_options[1] = 2; // len param 482 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 483 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 484 485 // log_dbg("new state %u\n", channel->state); 486 } 487 488 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 489 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 490 if (!channel) { 491 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 492 return; 493 } 494 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 495 496 // discard channel 497 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 498 free (channel); 499 } 500 501 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 502 // accept the other's configuration options 503 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 504 uint16_t pos = 8; 505 while (pos < end_pos){ 506 uint8_t type = command[pos++]; 507 uint8_t length = command[pos++]; 508 // MTU { type(8): 1, len(8):2, MTU(16) } 509 if ((type & 0x7f) == 1 && length == 2){ 510 channel->remote_mtu = READ_BT_16(command, pos); 511 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 512 } 513 pos += length; 514 } 515 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 516 // send back received options 517 // l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 518 // send back OK 519 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 520 } 521 522 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 523 524 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 525 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 526 uint16_t result = 0; 527 uint8_t config_options[4]; 528 529 // log_dbg("signaling handler code %u\n", code); 530 531 switch (channel->state) { 532 533 case L2CAP_STATE_WAIT_CONNECT_RSP: 534 switch (code){ 535 case CONNECTION_RESPONSE: 536 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 537 switch (result) { 538 case 0: 539 // successful connection 540 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 541 channel->sig_id = l2cap_next_sig_id(); 542 config_options[0] = 1; // MTU 543 config_options[1] = 2; // len param 544 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 545 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 546 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 547 break; 548 case 1: 549 // connection pending. get some coffee 550 break; 551 default: 552 // map l2cap connection response result to BTstack status enumeration 553 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 554 break; 555 } 556 break; 557 558 case DISCONNECTION_REQUEST: 559 l2cap_handle_disconnect_request(channel, identifier); 560 break; 561 562 default: 563 //@TODO: implement other signaling packets 564 break; 565 } 566 break; 567 568 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 569 switch (code) { 570 case CONFIGURE_RESPONSE: 571 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 572 break; 573 case CONFIGURE_REQUEST: 574 l2cap_signaling_handle_configure_request(channel, command); 575 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 576 break; 577 case DISCONNECTION_REQUEST: 578 l2cap_handle_disconnect_request(channel, identifier); 579 break; 580 default: 581 //@TODO: implement other signaling packets 582 break; 583 } 584 break; 585 586 case L2CAP_STATE_WAIT_CONFIG_REQ: 587 switch (code) { 588 case CONFIGURE_REQUEST: 589 l2cap_signaling_handle_configure_request(channel, command); 590 channel->state = L2CAP_STATE_OPEN; 591 l2cap_emit_channel_opened(channel, 0); // success 592 l2cap_emit_credits(channel, 1); 593 break; 594 case DISCONNECTION_REQUEST: 595 l2cap_handle_disconnect_request(channel, identifier); 596 break; 597 default: 598 //@TODO: implement other signaling packets 599 break; 600 } 601 break; 602 603 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 604 switch (code) { 605 case CONFIGURE_RESPONSE: 606 channel->state = L2CAP_STATE_OPEN; 607 l2cap_emit_channel_opened(channel, 0); // success 608 l2cap_emit_credits(channel, 1); 609 break; 610 case DISCONNECTION_REQUEST: 611 l2cap_handle_disconnect_request(channel, identifier); 612 break; 613 default: 614 //@TODO: implement other signaling packets 615 break; 616 } 617 break; 618 619 case L2CAP_STATE_WAIT_DISCONNECT: 620 switch (code) { 621 case DISCONNECTION_RESPONSE: 622 l2cap_finialize_channel_close(channel); 623 break; 624 case DISCONNECTION_REQUEST: 625 l2cap_handle_disconnect_request(channel, identifier); 626 break; 627 default: 628 //@TODO: implement other signaling packets 629 break; 630 } 631 break; 632 633 case L2CAP_STATE_CLOSED: 634 // @TODO handle incoming requests 635 break; 636 637 case L2CAP_STATE_OPEN: 638 switch (code) { 639 case DISCONNECTION_REQUEST: 640 l2cap_handle_disconnect_request(channel, identifier); 641 break; 642 default: 643 //@TODO: implement other signaling packets, e.g. re-configure 644 break; 645 } 646 break; 647 default: 648 break; 649 } 650 // log_dbg("new state %u\n", channel->state); 651 } 652 653 654 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 655 656 // get code, signalind identifier and command len 657 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 658 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 659 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 660 661 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 662 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 663 return; 664 } 665 666 // general commands without an assigned channel 667 switch(code) { 668 669 case CONNECTION_REQUEST: { 670 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 671 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 672 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 673 break; 674 } 675 676 case ECHO_REQUEST: { 677 // send back packet 678 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 679 break; 680 } 681 682 case INFORMATION_REQUEST: { 683 // we neither support connectionless L2CAP data nor support any flow control modes yet 684 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 685 if (infoType == 2) { 686 uint32_t features = 0; 687 // extended features request supported, however no features present 688 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 689 } else { 690 // all other types are not supported 691 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 692 } 693 break;; 694 } 695 696 default: 697 break; 698 } 699 700 701 // Get potential destination CID 702 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 703 704 // Find channel for this sig_id and connection handle 705 linked_item_t *it; 706 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 707 l2cap_channel_t * channel = (l2cap_channel_t *) it; 708 if (channel->handle == handle) { 709 if (code & 1) { 710 // match odd commands by previous signaling identifier 711 if (channel->sig_id == sig_id) { 712 l2cap_signaling_handler_channel(channel, command); 713 } 714 } else { 715 // match even commands by local channel id 716 if (channel->local_cid == dest_cid) { 717 l2cap_signaling_handler_channel(channel, command); 718 } 719 } 720 } 721 } 722 } 723 724 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 725 726 // Get Channel ID 727 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 728 729 // Signaling Packet? 730 if (channel_id == 1) { 731 732 // Get Connection 733 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 734 735 uint16_t command_offset = 8; 736 while (command_offset < size) { 737 738 // handle signaling commands 739 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 740 741 // increment command_offset 742 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 743 } 744 return; 745 } 746 747 // Find channel for this channel_id and connection handle 748 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 749 if (channel) { 750 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 751 } 752 } 753 754 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 755 switch (packet_type) { 756 case HCI_EVENT_PACKET: 757 l2cap_event_handler(packet, size); 758 break; 759 case HCI_ACL_DATA_PACKET: 760 l2cap_acl_handler(packet, size); 761 break; 762 default: 763 break; 764 } 765 } 766 767 // finalize closed channel 768 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 769 channel->state = L2CAP_STATE_CLOSED; 770 l2cap_emit_channel_closed(channel); 771 772 // discard channel 773 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 774 free (channel); 775 } 776 777 l2cap_service_t * l2cap_get_service(uint16_t psm){ 778 linked_item_t *it; 779 780 // close open channels 781 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 782 l2cap_service_t * service = ((l2cap_service_t *) it); 783 if ( service->psm == psm){ 784 return service; 785 }; 786 } 787 return NULL; 788 } 789 790 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 791 // check for alread registered psm // TODO: emit error event 792 l2cap_service_t *service = l2cap_get_service(psm); 793 if (service) return; 794 795 // alloc structure // TODO: emit error event 796 service = malloc(sizeof(l2cap_service_t)); 797 if (!service) return; 798 799 // fill in 800 service->psm = psm; 801 service->mtu = mtu; 802 service->connection = connection; 803 service->packet_handler = packet_handler; 804 805 // add to services list 806 linked_list_add(&l2cap_services, (linked_item_t *) service); 807 } 808 809 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 810 l2cap_service_t *service = l2cap_get_service(psm); 811 if (!service) return; 812 linked_list_remove(&l2cap_services, (linked_item_t *) service); 813 free(service); 814 } 815 816 // 817 void l2cap_close_connection(void *connection){ 818 linked_item_t *it; 819 820 // close open channels 821 l2cap_channel_t * channel; 822 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 823 channel = (l2cap_channel_t *) it; 824 if (channel->connection == connection) { 825 channel->sig_id = l2cap_next_sig_id(); 826 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 827 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 828 } 829 } 830 831 // unregister services 832 it = (linked_item_t *) &l2cap_services; 833 while (it->next){ 834 l2cap_service_t * service = (l2cap_service_t *) it->next; 835 if (service->connection == connection){ 836 it->next = it->next->next; 837 free(service); 838 } else { 839 it = it->next; 840 } 841 } 842 } 843